Motor control system



Dec. 5, 1933. w. F. EAMES 1,937,816

MOTOR CONTROL SYSTEM Filed Oct. 29, 1924 3 Sheets-Sheet 1 WITNESSES: INVENTOR ATTORNEY Dec. 5, 1933. w EAMES 1,937,816

MOTOR CONTROL SYSTEM Filed Oct. 29, 1924 3 Sheets-Sheet 2 L .58 26 3.9 7 g 7 L 3.5 4/\/rm T 40 Z8-oat ITNESSES: INVENTOR ATTORNEY 1933- w. F. EAMES 1,937,816

MOTOR CONTROL SYSTEM Filed Oct. 29. 1924 3 Sheets-Sheet 3 WITNESSES: I lNVENT-OR E%y/ Mam? 550/7765.

Patented Dec. 1933 UNITED; STATES PATENT. orricc 1 1,937,816' "Moron CONTROL SYSTEM" I 7 William F. Eames, Pittsburgh, Pa, assignor w Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application October 29, 1924. serial No. 746,473 ao'claims. (Cl. 187-29) My invention relates to systems of motor control and it has particular relation to such systems as are employed in connection with elevators, hoists and similar machines.

,5 An object of my invention is to provide a semi-automatic control for one or more elevators ina group whereby the schedule. of operation and efficiency of the system are improved.

According to my system, a person entering an 10 elevator car designates the floor number at which it is desired to stop and the car operator pushes a button or switch corresponding to that floor or landing. A number of other persons enter the car under similar conditions and,

: when there is a suflicientload, 01 when a certain time interval has elapsed, the operator closes the door and actuates a button or switch to start the car. The car accelerates andtravels to the next succeeding: floor at which it is desired to stop. The car stops automatically and after this floor has been served and the gate .again closed, the elevator proceeds to the other desired floors, successively. Meanwhile, if any personat; any floor desires to enter the elevator 86; he may do so by actuating a call button, whereupon the first car to arrive stops at that floor. If any car is filled or for some reason the operator does not wish to stop, he may press a nonstop button which permits the car to pass the floor; in which case the 'next succeeding elevator car will pick up the waiting passenger. In connection with this system, means is provided for effecting accurate car stops, as hereinafter set-forth.

My invention will be described in connection with the accompanying drawings in which Figure 1 illustrates, diagrammatically, the mechanical arrangementof an elevator designed in accordance with my invention, 7 40' Fig. 2 is a diagrammatic view of the main circuits and apparatus embodying my invention, Fig. 3 represents, diagrammatically, certain of the control circuits employed in connection with the system of Fig. 2 and Fig. 4 isa typical lay-out of push-button elevator control for serving one floor and three elevators.

In Fig. 1, a car 1a is shown as connected to a counterweight 20. by means of a cable 3a running over the usual drum 41a and sheavewheel; 51:. The drum 4a is provided with a magnetic brake 611. One hatchway wall 7a is also co ventionally;illustrated, together with control apparatus more fully hereinafter set forth.

55 Referring particularl-yto Fig. 2, I --emp1oy a energize relay 32, and will engage'fan operating a a e q te si ie e 'n n'g e. l 'i he et h vin an r flr 2 e n t i t; cuit with the armature 3J of a direct-current generators. The enerator, is preferably pro vided with a cumulative series field-magnet winding 5 and a separately excited field-wind; ing the excitation of which may be varied by means of field resistors 7 and9.. The motor 1 is provided with a separately e icited field magnet winding 11. eiiciter 12 for the mm 957 machines 1 and mounted on the generator armature shaft. The generator and excitr are operated by suitable means as, for example, the illustrated inducti'on'motor 13. Relays 14' arid 5 a mployed as hereinafter desecribed to control the generator field excitation. j Revers ing switches2l, 2'2, 23 and 2,4 are provided also for controlling the generator field excitation in a familiar manner.

Referring to Fig. 3' the fup and doWn push- 7 buttons or switches 25'an'd 26', res ectively,- are connected for controlling the corresponding reversing or directional switches to initiate the operation of th lvitor car thedsired dilftion. A plurality of door switches 27, of a go familiar character, are adapted to preventstart ing the car with ny door open; Tneseswitcnes Connor me operat ng coil or a relay s for the purpose stated. relay, however, permits movement within prescribed limits at any floor, in accordance' with theop'e'ration or me floor-landing switches :29 30. These switches are rendered inoperative normall by means of retiring magnets or coils 31, illustrated i'nIFigs. I andZ,

and which are energized when the elevator is operating at high speed. The switches 29 and- 3Qare retired bodily so that normally they will i not engage operating cams incited in then'iitnway. Thertiri'ngmagnets are energized by rmy 32 up n the clos re or the dot; switch'eslzh to effect the energ zatiqn 'of the operating coil of relay 32. Switches '29 and 30 are initially in their illustrated positions when the" up" direction coils 21' and 23 are fi'rst' energized. when the car is, substantially at re'st adjacent t6 an landing, the switches' z 'and 30 will be released by the opening oi stop' switches 33, which decam 35 that is located inth hatchway 58 111115- tratedinFig'. 1 d

The operation of the elevator is effected by meansof up anddown relays i'ifi and 37' are adaptedtobeself-holding. That is to sa no of the elevator at slow 35 V actor is described in thecopending application Company and in the copending application of way and another portion 44 carried by the elevator car. A switch'or relay of similar charof Ray P. Higbee, Serial No. 551,483, filed April l1, 1922, which has maturedinto a Patent No. 1,561,232, November 10, 1925, and assigned to the Westinghouse Electric and Manufacturing John F. Clancy, Serial No. 559,997, filed May l1, 1922. y when the car is adjacent thereto, whereby the magnetic circuit is completed and theoperating coil 45 becomes effective to actuate-the relay.

One of. the relays 33 for stopping the cars is provided at" each landingfor each car. These relaysare preferably of'the same type as the slow-down relays 42 By this means, efiective control is provided for the elevator without the noise incident to mechanical engagement of cam-operated switchesfi 5 Referring to Fig. 4, push-buttonsor, switches 46 and 47 are mounted'at each landing" to'contrcl the stopping of an approaching car.1 These switches respectively operate the relays 48 and 49 to setup' circuits for" the-corresponding slow- "down' and stop relays; For each car-floor in each elevator car there is a push-button switch 5 1, 52 ,or53 for controlling suitable transferbe hereinafter described. This relay r'eleasesre lay 58, which connects resistor 9 in'shu'ntrela tionfto the generator field-winding 6.

type relays 54, 55 or 56 respectively,'whereby the car operator may cause the car to stop'at the desired floor or floors at which passengers on the cardesire to leave the car.

'My invention will be best understood from the following description of operation; Assuming the elevator 'totbe'at the first or main floor, its upward movement is effected by the operation of switch 25', whereby reversing switcheszland 23 are closed to energize the generator field winding '6. Simultaneously therewith, relay 36 is closed and remains closed after switch 25 is released. Relay 28 is energized through the dircuit of the doorswitches 27, but theholding circuit through -interlock 2l-in and" landing switch 29 maintains the direction switches in their operative positions. Theelevator is thereafter accelerated by the'closure of field acceler= "a'ting relay 15 which excludes generator field resistor 7.; 1 g i Relay 'l5'is controlled by relay 14, the, operating coil of' which is in circuit with the door switches 27, so that upon closure of the door switch circuit, relay 14 is picked up and in turn energizes accelerating relay 15.1 It willbe noted thatthe operating coil of relay 14 is also controlled by the slow-down relays 42, which are normally closed but become effective to control the generator field excitation andslowvdown the motor, as hereinafter described. l

" "The car travelsfupward' until one of the slow} down relays '42 becomes effective in a manner to lied-movement of the elevator effects the opening of the stop 'relay'33, which de-energizes re- Such a relay becomes operative only Contin- ,lay 32, thereby interrupting the circuit of the retiring coils 31 of the landing switches.

The magnet cam or armature 44 is of suitable length to maintain the slow-down and'stop relays in their inoperative positions in bringing the car to the landing position. Under the present circumstances the switches would be arranged to stop the car slightly shortof the land ing, but, before actually stopping, the levelling switches 29 would be effectiveto continue the car .iovernent to the exact landing position without interrupting the motor circuit. It is obvious, however, that suitable positioning of relays 43 and 33 and proper regulation or the motor will permit the: car to stop level with the fioor without theuse of the levelling device, In acthe herein described slow-downandstop relays 42 and 33 which may be adjusted tostop possible to effect, automatic landing by the use the" car at any desired point. .I have found that through the use or a generator having proper field characterist cs, the car will'always stop accurateiy with ect-to the landing. Where ex treme accuracy is required, it may be desirable to provide the additional levelling ieatu.

In the illustrated system, if the carrtends to stop below the landing, it will be brought to the landing when the door switch 2' is opened,

which e ablishes an automatic landing or levelling circuit comprising reversing switches 21 and thereby re1easing relay 28, the lower member or 23 and switches 29 and- 30, which are now in their lower closed positions and controlled by the levelling cam 35. If the car stops above the floor, switches Zfiand 3G assume their upper closed positions to complete'a circuit through'the uppercontact members of relay 28 and energize th down reversing switches 22 and 24'. This general method of levelling; or effecting an automatic landing, is familiar to those skilled-in'the art, but certain --additional novel features will appear'from a further description of my invention. order to insure the generation of sufficient voltage to lift heavyloads at slow speed, a series relay 59 of a well-known type is provided for shunting a portion of resistor '7.

Further details of automatic control are illustrated iirl lgure 4. If the operators push button 5i mine car is ciosed, transfer relay 54 is energized and holds itself closedthrough interlock 62; Thisrelay provided with. upper contact members 63 that connect all the slowdown and stop'relay coils 45, 64, 5-5 and 66 of the correspending elevator in circuit. When the car approaches any floor from either direction of travel, the armature member carried by the car arriving adjacent the slow down relay for'the direction in which the car is moving; completes the magnetic circuit previouslyreferred to and energization of the'proper slcw dcwn switch (Fig. 3). The armature member 44 then becomes effective to actuate the stop relay 33; Opening thefdoor closes door switch 6? and effects the operation of a relay 6S1to interrupt the holdingcircuit or the transierrelayfie and thecar isthen ready to start again in the same will continue its upward movement. Relay -71 is held closed by relay 36- and if a waiting passenger actuates the upfloor button 46, the oper ating coil 72' effects the closure of "relay 48, thereby completing a circuit through relays48, 71 and 74, the lower contact members '75 ofrelay 54 and the slow-down and-stop relay coils 45, 64,

and 66. Whenthe car approachesthe floor, it will automatically stop to'take on the waiting passenger, unless the car operator actuates the non-stop switch 76, which actuates relay 74 to interrupt the above traced slow-down and stop circuit and allows the car to continue its'movement'. In the latter event, if elevator #215 the next to approach the landing it will be automatically stopped, since a slow-downand" stop 'circuit is completed through relays 48, 81, 84

and 55 to energizethe slowdown and'stop coils 85 to 88, inclusive, which control #2elevator in the same manner that #1 elevator was controlled.

'Fig. 4 illustrates the typical connections corresponding to any single landing that is to be served in a system comprising three elevators. Similar connections are provided for each landing'to be served and, therefore, it is considered unnecessary to duplicate these connections for a plurality of landings. The up and down buttons '46 and 47 at each landing control all the eleopen. When any car stops at the desired landing, the opening of the landing door closes the corresponding door switch 67 to energize the op-- erating coil of the relay 68, which establishes a circuit for the retrieving coil '90 to effect the opening of relay 48; thus governing all cars travcling in the up direction and resetting relays 54, 55 and 56'. This operation does not'efiect the control of cars traveling'in the downdirection. These cars are under the' control of relays 91, 92 and 93, which are in circuit with the retrieving coil 94 for opening relay'49. This arrangement becomesnecessary in order that there will'be no interference with the operation offcars traveling in the opposite direction to those intended to be stopped. 'It ismy intention that all the elevators starting in a given direction will continue to the end of the car travel as previously set forth and likewise cars coming in the opposite direction respond to callsof passengers desiring to travel in. that direction.

Such an arrangement is adapted to establish" the ,7

most economical and eflicient service schedule.

It is believed that theeffectiveness and utility of my, system will be apparent to those skilled in the art and that modifications mayv readily be made therein without departing from the spirit and scope of my invention. 1

I claim as myinvention: V

1. In an elevator system, the combination with a car and controlling meanstherefor comprising an -up and a down switchin the car, of a. call switch. at each. landing}, a plurality of relays for each landing responsive to the call switch for In accordance with my system,

controlling said car, and an armature member carried by said-car for rendering said relays efl'ective." V

2. In an elevator system, the combination with a car and'controllingmeanstherefor, of a call switch at each landing, a plurality of --relays for each landing responsive to the call switch for controlling saidcar, and an armature member. carried by saidcar for rendering said relays effective. a v 7 3. In an elevator system, the combination with a :car and controlling means-therefor, of a call switch, a plurality of relays responsive to the callswitch for controlling said car, and an armature member carried bysaid car for rendering said relayseffective. i

4. In an elevatorsystemthe combination with a car and controlling means therefor comprising an up and a down switchin the car,'of a call switch'at each landing, a plurality of relays responsive to the call switch for controlling said car, and an armature member' carried bysaid car for 'rendering said relays-:eflective. w r 5. In an elevator system, the combination with a car and controllingmeans therefor comprising an up and a down switch inthe car, of a call I switch at each landing, a plurality ofrelays at each landing responsive to the call switch for controlling said car, and an armaturemember carried by said car for rendering said relays eflective to slow down and stop said car.

6. Inan elevator system, the combination with g a car and controlling meanstherefor, of acall switch at each landing, a plurality of relays at each landing responsive to the call switch for controlling said car; and an armature member carried by said car for rendering said relays effective to slowdown and stop' said car.

g '7. In an elevator system, the combination with a car and controlling means therefor, of'a call switch, a plurality of relays responsive to the call switch for controlling'said car, and an armature member carried by said car for rendering said relays effective to slow down and stop said car.

v 8. In an'elevator system,the combination with a car and controlling means thereforcomp'rising an up and a down switch in thecar, of a call switch at each landing, aplurality of relaySresponsive to the call switch for controlling said caryand an armature member carried by said car-for rendering said relays'efiective to slow down and stop said car.

9. In an elevator system, the combination with a car and controlling means therefor comprising an up and a down switch in the car, of a call switch at each' landing, and electroresponsive'means partly on'the car and partly in the hatchway responsive to the call switch for controlling said car. I

10. In an elevator system, the combination with a plurality of cars and controlling means therefor. comprising an up and a down switch in each car, of a call switch at each landing, a plurality of relays at each landing responsive to the call switch for controlling said cars, armature members carried by said cars for rendering said relays effective, andmeans carried by each car for rendering certain of said relays ineffective.

11. Inkan, elevator system, the combination 7' with a'plurality of cars and controlling means therefor, of a call switch at each landing, a plurality of relays at each landing responsive to the call switch for controlling said cars,

- to thegcall 'switch for controlling said cars,

' of a call switch at each landing,

' plurality of relays at armature members carried bysaid cars for rendering said relays effective, and means carried by each car for rendering certain of saidrelays inefiectiva 12. In an elevator system the combination with aplurality of cars and controlling means armaturemembers carried by said cars for rendering said relays effective to slow down and stop said cars and ,means carried by eachcar for rendering certain of said relays ineffective.

14.- In an' elevator 'system,'t he combination with aplurality of cars and controlling means therefon, of 'a call switch at each landing, a each landing responsive to the call switch for. controlling said cars,

armature members carried by said cars for ren dering said relays effective to slow down and stop'said cars and for rendering certain of said relays ineffective. 15. In an elevator system, the combination with a plurality of cars andcontrolling means.

, therefor, comprisingan Up and adown switch in the 'car, of a call switch at each landing, a. plurality of relays responsive to the call switch for controlling said canarmature members, car- 'ried by said cars for rendering said relays effective to slowdown and stop said cars, and means carried by each car for rendering certain' of said relays ineffective. f f

16. In an elevator system, the combination J with a car and controllingmeans therefor comprising an up and a down switch in the car, electroresponsive means responsive to the call switch for con- 7 trolling said car, and an armature member carried by said car for, rendering said electroresponsive means effective. v, f

17.. In "anqelevator system, the combination with a car and controlling means therefor, of a call switch at each landing, electroresponsive means responsive to the'call switch for 'controlling said car, and an armature member carriedv by. said car forre'ndering said e'lectroresponsive means effectivei 18, In an elevator system, the combination with a car and controllingv means therefor 'cornprising an up and a 'downswitch inthe car,

- of a call switch at each landingfelectroresponsive means responsive to, the call switch for controlling ,saidcar, and'an armature member carried by said car forjrendering said 'electroresponsive meansfeffec'tive to slow down and stop said car. i V r l9. In an elevator system, the combination withja car "and controlling means, thereforf'of a call switch at "each landing, electror'esponsive means" responsive to the call switch for controlling said car, and an armature member can,

ied by said car 'for rendering said,electrore sponsi e means effective to slow down and stop said car. f I 20 .In, an elevator system, the combination means; carried by, each car with pluralityiof cars and controllingmeans therefor comprising an up anda down switch in the car, of a call switch at each landing,- electroresponsive means responsive to the call switchfor controlling said cars, armature members' carried by said cars for rendering said 'electroresponsive means effective, and means carried by each car for rendering certain of said relays ineffective; 7 "21.' In an, elevator, system. the combination with a plurality of cars and controlling means therefor, of ajcall' switch at each landing, relaysresponsive to the call switch for controlling said .cars, armature members carried by said cars for rendering said relays effective, and means carried by eachcar-for rendering certain of said relays ineffective. V 1 5 22. Inian elevator system, the combination with aeplurality: of carsand controlling'means therefor comprising an up and a down switch in the car, of a call switch at each landing, relays responsive to the call switch for controlling said, cars, armature members carried by said cars for rendering said relays effective to slow down andstop'said'cars, and means carried by each car for rendering certain of said relays ineffective.

23, In an elevator system, the combination with a car and controlling means therefor, of a call switch at each landing, and electroresponsive means partly on the car and partly. in the hatchway responsive to the call switch for controlling said vcar.-

24;.In an elevator system, the combination with a car andcontrolling means therefor comprising an; up anda down switch'inthe. car, of

means effectiv'eto slow down and stop said car.

t 25, In an elevator system, the combinationwith a car and controlling means therefor, of a call switch ateach landing, and electrorespona sive means partlyon the carand partly in the hatchway andmeans responsive ;to' the call switch -for rendering a said electroresponsive means effective to' slow down and stop said car. i

. 26;In-- an elevator system, the combination witha plurality of :cars and controlling means therefor comprising an up and down switch in each-car, vof a call switch fat each landing, electroresponsive" means partly on, the car and partly, in the hat'chway responsive to the call switch for controlling saidcars, and "means carriedby each car for rendering said car electro responsive means ineffective to stop said car,

' 27.- In 'anelevatbr system, 7 the combination with a plurality of cars and controlling means therefor,. of a call switchateach landing, electroresponsive means partly on the car and partly in the hatchway responsive to the call switchfor controlling said cars, and means carried by each car for rendering said electroresponsive means ineffective to stop' said car.

"28; In an elevator system, the combination with a plurality of cars and controlling means rtherefor 'comprising an up and adownswitch in the car, of a call switch at each'landing'; electroresponsive means partly on the car and partly in the hatchway and means responsive to the call switch for rendering said -electroresponsive means effective to slow down andstop said cars, and means carried by each car for rendering means comprising a' switch, a coil normally ineffective to controlsaid switch means on one of said members, and a magnetizable plate mounted on the other of said members for rendering said coil effective to actuate said switch when said coil and plate are adjacent.

30. In a control system for elevators operable between a plurality of floors, a ear member, a hatchway member, means for starting said car,

means for stopping said car comprising a switch and a coil normally inefiective to actuate said switch mounted on one of said members and a magnetizable plate on the other of said members for rendering said coil effective to actuate said switch when said coil and said plate are adjacent, and manually operable means at said floors for energizing said coil.

WILLIAM F. EAMES. 

